Jenine Hulsmann

Jenine has advised on some of the most high-profile and complex M&A transactions of the past decade, securing Phase 2 clearances from both the European Commission and CMA.  With a particular focus on the technology, pharmaceutical and energy sectors, she has represented corporations on a wide range of behavioural antitrust matters and investigations, as well as on competition appeals and litigation. A former secondee to the UK telecommunications regulator, she is a trusted adviser on regulation, foreign investment and national security issues.

Jenine is ranked in Band 1 by Chambers UK 2026 and is recognised as a leading competition lawyer in Chambers Global and Chambers Europe. She is included in the “Hall of Fame” in Legal 500 with a “stellar market reputation”. She was recently shortlisted for the “Innovative practitioner” award at the FT Innovative Awards 2025 and for “Lawyer of the Year” at the Global Competition Review Awards 2024.  She was “Highly Commended” for “Private Practice Lawyer of the Year” at the Legal Business Awards 2024 and was also included in GCR’s Women in Antitrust List 2025. Described by clients in Chambers as “an exceptional merger control lawyer” and “one of the smartest, if not the smartest lawyer, I've worked with when it comes to strategy and timing”, Jenine is noted for being “relentless in her pursuit of getting your deal through” and “a Swiss army knife of strategic vision, tactical execution and just plain smarts.”. In Legal 500, clients state that Jenine is “highly commercial and skilled at applying the law to client needs. She is also an excellent communicator and is well respected by senior managers within my business as much as by external regulatory stakeholders.” She is a member of the City of London Law Society Competition Law Committee.

Representative experience at Weil and from her previous firm includes:

• Microsoft on the merger control aspects of its investment in OpenAI and the CMA study into AI Foundation Models
• Microsoft on the merger control aspects of its investment in Mistral AI
• Virgin Media O2 on the €17.5 billion joint venture between Vodafone and Three UK, which was cleared by the UK CMA following a complex Phase 2 investigation
• Microsoft on its $68.7 billion acquisition of Activision Blizzard, Inc. This landmark merger control matter won Global Competition Review “Matter of the Year,” “Merger Control Matter of the Year: Americas” and “Merger Control Matter of the Year: Europe” in 2024.
• Advent International and NielsenIQ before the European Commission on NielsenIQ’s combination with GfK, winning a rare conditional Phase 1 approval
• Eutelsat on its $3.4 billion combination with OneWeb creating a leading satellite service provider
• Liberty Global and Telefonica on a joint venture with InfraVia to create nexfibre
• Telefónica SA on the £31 billion merger of O2 and Virgin Media with Liberty Global plc, including a reference from the European Commission and CMA Phase 2 unconditional clearance
• A number of CMA investigations under the Competition Act 1998 in relation to alleged excessive and unfair pricing and anti-competitive agreements in the pharmaceutical sector
• An intervenor, in the ground breaking CK Telecoms UK Investments v Commission appeal against the European Commission’s Phase 2 decision prohibiting the 3/O2 merger
• The CMA market investigation under the Enterprise Act 2002 into funeral markets
• Inmarsat on its acquisition by Triton Bidco for £2.6 billion, including the public interest intervention investigation under the Enterprise Act 2002
• Tele 2 on the unconditional EU Phase 2 clearance of the merger between Tele2 Netherlands with T-Mobile Netherlands
• A European Commission investigation into cross-border access to pay TV
• EE in obtaining unconditional Phase 2 clearance of the GBP£12.5 billion acquisition by BT Group plc
• EDF on obtaining State aid clearance for Hinkley Point C, including the subsequent appeals
• Imagination Technologies Group PLC on its takeover offer by Canyon Bridge